The present invention relates to thermostatically controlled faucets and more particularly to thermostatic faucets operated by temperature responsive feedback controlled servomechanisms.
Since shortly after the time that hot and cold running water first became a common feature of architecture, there has been an awareness of the occasional inconvenience that can result from a sudden undesirable change in temperature or pressure of the pressurized water in either of the lines supplying water to a faucet. In some cases, the resulting change in the temperature of the mixed outlet water can result in discomfort to the user of the faucet. The discomfort can be particularly pronounced when the valve is a shower mixing valve and the user is within the shower stall. A sudden pressure drop in the cold water line, such as that which frequently occurs when a toilet is flushed, will cause a sudden increase in the temperature of the shower water, requiring the user to move quickly away from the stream of water.
Several faucets and mixing valves have been developed in an attempt to reduce or eliminate this problem. They include valves provided with thermometers, thermostats or stop mechanisms.
One design offered in the past as an attempt to ameliorate this problem is the provision of a thermometer in the escutcheon of the faucet to notify the user of the temperature of the water. An example of this type of faucet is disclosed in U.S. Pat. No. 3,960,016 (issued June 1, 1976). The thermometer will warn the user of gradual temperature changes or of changes that occur while the user is not in contact.
A primary feature of the present invention is that it provides a reliable compact thermostatically controlled valve wherein all the valving elements and temperature sensing elements can be provided within a control handle. An advantage of this configuration is that a handle assembly may be adapted to be fitted to existing single handle faucet sockets. Another advantage of this configuration is that it permits easy access to internal valve components for servicing and repair. Another advantage of this configuration is that it permits the use of a temperature indicating element visible on the exterior of the handle to indicate the temperature of the mixed water being discharged by the valve. Still another advantage to this configuration is that it permits providing the control handle with a compact temperature preselection mechanism. Still another advantage to this configuration is that it permits providing the control handle with a selectively disengagable stop mechanism limiting the maximum hot water temperature setting to prevent the user from unintentionally preselecting a temperature greater than a predetermined maximum temperature.
Another feature of the present invention is that it provides a servomechanism valve having a movable proportioning valve which is not affected directly by changes in pressure in either of the supply lines, but instead is affected only by the temperature of the mixed water. The advantage to this design is that the valve will produce a more nearly isothermal output than previous servomechanism valves.
It is therefore one object of the present invention to provide a reliable thermostatically controlled valve using a feedback controlled servomechanism.
Another object of the present invention is to provide a compact thermostatically controlled valve that may be mounted within the control handle of a faucet.
A third object of the present invention is to provide a handle module which contains a thermostatic valve assembly and which may be easily adapted to be fitted to the socket of an existing single handled faucet, the module replacing the control handle and some adjacent hardware of the existing faucet.
Another object of the present invention is to provide a thermostatically controlled proportioning valve that will produce an isothermal output even under extreme variations in temperature and pressure in the supply lines.
Another object of the present invention is to provide a single handle faucet having a temperature indicator mounted to the handle.
Another object of the present invention is to provide a servomechanism valve assembly having long and narrow fluid passageways which valve assembly is not susceptible to failure due to the accumulation of particles along the passageways.
Still another object of the present invention is to provide a thermostatically controlled faucet having a selectively disengagable stop mechanism limiting the maximum hot water temperature setting.
Still another object of the present invention is to provide a thermostatically controlled faucet with a restore mechanism to reset the thermostat to a temperature at or below a predetermined maximum level when the faucet is not in operation.
Still another object of the present invention is to provide a faucet having a control handle regulating the total discharge rate of water from the faucet, a thermostatically controlled valve, a temperature indicator, and a selectively disengagable stop limiting the maximum hot water temperature setting wherein the valve, the indicator and the stop are each mounted within the control handle.